How did Yamaha fix the 2005 YZ250 Steering issue for 2006

Dekester

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Jan 2, 2007
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Was the angle changed in the steering head on the frame itself or was it an offset in the clamps? Yamaha website does not specify, only states that they changed the angle.
 

Matt90GT

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May 3, 2002
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the 2 strokes are the same frame from 05-07.

The only difference from 05-06 is the front forks are the SSS (05 is the AOSS) and they use a 2mm wider clamp than 05.

from 06-07 they use a 1.5mm longer rear shock which will make it turn quicker - steeper rake.

But keep in mind with any new yamaha - GET RID OF THE 739 tire up front!
 

Dekester

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Jan 2, 2007
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I have some questions. The Yamaha website states that there was a change in the pitch of the forks. If you are 100% sure the frame is identical, then there must be an offset in the 06 triple clamp.

You also stated the clamps are 2mm larger in 06. They switched from 46mm to 48mm back in 04. Unless the outer diameter of the forks (where triple clamp attaches) changed from the AOSS to the SSS, that does not make sense. On the exterior, the 05 and 06 look to be identical from what I see in pictures.

The reason I am so thorough in asking is that I am not sure if I want to buy an 06 when my 05 is highly modified. I could buy the 06/07 forks and shock used or buy an 06 and swap as much as I can over. Obviously the frame/triple clamp changes impact my decision making.

Thanks in advance.
 
B

biglou

Apples and oranges here, but my 05 YZ250 handles infinitely better than my 04 YZ450F did. And you're right about the switch from 46-48mm forks in 04. I've got the same top clamp on my 05 that I had on my 04. 450F-250 2T.
 

Matt90GT

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May 3, 2002
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I did not say longer, WIDER. The forks are spread apart 2mm in the 06-07 bikes vs the 05s.

Yeah exterior on the Aoss and SSS forks looks the same. But they are NOT! Internally they are very different. and the SSS forks work way better. I had an 05 and now 06 250f.

if you want to know all the specific changes yearly on the yamaha bikes, go to a dealer and get the "technical seminar update book" for the new year. It list EVERY change bike by bike and reasons for the changes. Even things like lighter gears, hollow shafts, different spoke diameters, etc.
 

Dekester

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Jan 2, 2007
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MattGT90 - Thanks for the reply and clarification. I actually said larger, not longer. I interpreted your wider statement as diameter of individual fork and not distance from each other. I will definitely get the technical seminar update book. Thanks for the heads up on the book.


Pidro el pirata - The 05 front end tended to push in turns.
 

2strok4fun

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Apr 6, 2002
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Currently, what are the steps taken to improve the handling of the 05's barring front end replacement? Can an eccentric axle like Rekluse offers help?
 

Matt90GT

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May 3, 2002
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spend some time setting up the suspension if it pushes. Try different tires. loosen up the rebound, set the sag like 95mm instead of the usual 100-105 and then play with the height of the forks in the clamps
 

BSWIFT

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I've heard that you can get the offset triple clamps to help the steering. I know a guy that did that and swears by it. However, he works at a dealership and gets a big discount on parts. I've had my suspension done by MX-Tech and the improvement is vast. Having the front and rear revalved on the 05 has made improvements everywhere. Definitely get rid of the 739.
I haven't ridden the 06-07 but reports indicate the suspension change is very noticeable when compared to the 05 and earlier YZ's. As Big Lou said, the 05 is better than the 03-04 YZF450's.
 

Rcannon

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22.5 offset triple clamps do help the turning of the 06. I was never able to come to terms with the way my 06 cornered until I changed these. At 22.5 the bike feels like an rm suzuki, but has improved stability in the straights.

First step has to be to junk the stock front tire. Then set the rear sag. Triple clamps are a last resort and rather expensive, but I love mine.
 

SpDyKen

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Rcannon said:
22.5 offset triple clamps do help the turning of the 06. I was never able to come to terms with the way my 06 cornered until I changed these. At 22.5 the bike feels like an rm suzuki, but has improved stability in the straights.

First step has to be to junk the stock front tire. Then set the rear sag. Triple clamps are a last resort and rather expensive, but I love mine.
R, What is the offset of the OEM clamps, i.e. which way does the 22.5 mm clamps change the geometry?

Matt, thanks for the info. on the shock length. 1.5 mm is substancial; so that was changed for '06, no chanhe for '07, correct? Do you know if all model YZ & YZF shock lengths changed (and continue to be consistant,) or does each model have a unique shock length? I know the damping internals all vairy.
Thanks for your insight. Ken
 
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Matt90GT

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no from 06-07 the shock is longer by 1.5mm (2007 change).

again, get the technical seminar update books for 06 and 07 that will get you all the changes from 05-07

stock offset is 25mm if I remember correctly
 

SpDyKen

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Matt90GT said:
no from 06-07 the shock is longer by 1.5mm (2007 change).

again, get the technical seminar update books for 06 and 07 that will get you all the changes from 05-07

stock offset is 25mm if I remember correctly
Thanks, Matt. I don't have a cooperative dealer near me presently, so I appreciate the info. you've given me. I had not seen that mentioned anywhere else as a change for '07. I guess I'll be looking for an '07 shock. (I'll also try to get my hands on one of the technical update books, as well)
 

Rcannon

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This thread sounds like it is talking about two different bikes.

The 250f four stroke did get the longer shock. The 2 stroke 250 has slightly stiffer fork valving but no different length shock.

Stock offset is 24mm.

Offset changes are really fun. Even after owning the different clamps I would still like one of the Recluse axle's to play with. It makes a huge difference.

It would take pages to describe everything that changes with an offset change.

My yz's feel like they handle quicker, yet are more stable. No one believes this until you try the bike. Front tire selection becomes much less critical.

The rear spring preload (sag) had to be set just right. I felt like the set up was more forgiving with the stock triple clamps.
 

SpDyKen

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Hello Rcannon,
Your mention of the 250F is the first reference to that model. All prior discussion was implied to be about the YZ250. I didn't think the shock length had been changed on it. Thank you for your clarification.
KW
 

Matt90GT

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May 3, 2002
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New for 2007:
Modifying thickness of both inner and outer fork tubes and revising damping settings provides fantastic bump absorption and comfort while shaving weight.
Lightening the rear shock with aluminum components takes off more weight, and revised settings complement the ones in the fork.
A light and strong ProTaper aluminum handlebar in adjustable mounts adds comfort and control.
A new jet needle in the 38mm Keihin PWK carburetor boosts bottom-end and mid-range response.
Use of lighter, box-head bolts throughout the chassis eases maintenance while reducing weight and increasing performance.


I thought the suspension changes was with all the YZ lineup. I have heard other places mention it, but again I have not looked into the update books for the last year or so.

Here is a video also:

http://www.transworldmotocross.com/mx/features/article/0,13190,1515767,00.html
 

Rcannon

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Nov 17, 2001
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Transworld is never a great source for new info. Really, none of the magazines are. They are all 3 months behind. Often times a spec can change after they have published the info on new models.

The 2 stroke shocks stayed the same. Honestly, the bike needed no geometry changes. I love the 22.5 triple clamps. However, it would not surprise me if you rode the bike and thought I was nuts for changing. The difference is cool for me, but I dont know if everyone would like it.
 
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